Paper Size Detection - Ricoh FT4430 Service Manual

16 April '88

3. Paper Size Detection

The paper size dial controls side post positioning and paper size detection.
When the paper size dial [A] is rotated, the cam groove [B] moves the size
lever [C], which repositions the guide posts [D]. When the dial reaches a
standard paper size, one of the actuator plates [E] enters the paper size
sensor [F]. At the same time, the pin [G] on the leaf spring [H] drops into a
notch on the inside rim of the dial and the positioning switch [1] deactuates.
When the positioning switch opens, the scan signal is applied to the LCT
paper size sensor. The paper size sensor then reads the pattern of the
actuator plate and sends paper size data to the copier's CPU.
When the paper size dial is positioned at a non-standard paper size, the
positioning switch is actuated (closed). In this case, the LCT cannot be used;
the Load Paper indicator lights and no paper size is displayed on the
operation panel. This prevents the skewing that would occur if the guide
posts were not at the correct position.
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